1. Field of the Invention
The present invention relates, in general, to a method and apparatus for skinning the casing from encased frankfurters and the like.
2. Information Disclosure Statement
Frankfurters are typically manufactured by placing the desired ingredients in an elongated plastic tube or the like (often referred to as the "skin" of the frankfurter). The encased strand or chain of frankfurters is then processed or cooked and the plastic tube or skin is then removed from the processed frankfurter prior to packaging. Frankfurter skinners or peelers have been provided for conditioning and removing the skin from processed frankfurters. Such frankfurter peelers or skinners are well known to those skilled in the art and typically include a steam conditioning unit for applying steam to the frankfurters before the skin or casing is slit, and subsequently compressed air and/or a vacuum unit is utilized for removing the skin. A typical apparatus for skinning a chain of sausages and the is like shown in Garey, U.S. Pat. No. 3,312,995, issued Apr. 11, 1967.
One problem common to many such frankfurter peelers is that difficulty has been encountered at the twist points (i.e. the twisted portions between the kernels which attach the ends of the frankfurters one to another) in slitting the round end of the frankfurter casing deeply enough toward the twist so that harder to peel products may cause a problem. Another problem is that by the time the chain of frankfurters reach the vacuum unit the casings are not sufficiently loose from the kernels so that the casing will not separate readily from the kernels when the vacuum is applied to the casings.
A preliminary patentability search in class 452, subclass 50, produced the following patents which may relate to the present invention; Martin, U.S. Pat. No. 2,369,360, issued Feb. 13, 1945; Menghini, U.S. Pat. No. 2,954,579, issued Oct. 4, 1960; Brendle et al., U.S. Pat. No. 3,055,045, issued Sep. 25, 1962; and Klyce, U.S. Pat. No. 3,487,499, issued Jan. 6, 1970.
Martin discloses a sausage skinning machine which has a rotary cutter along a straight path of the chain of sausages at the bottom thereof. Also, the machine has a pair of knives that are mounted in spaced relationship on the periphery of a roller and which knives cut the tie string (twisted portion between the kernels). In addition, the machine has a separate knife which cuts the skin or casing at the top of the sausage chain. Thus, separate operations are provided, one for cutting the twisted portions and the other for cutting the skin or casing.
Menghini discloses a frankfurter skinning apparatus which includes an intermediate disk member and a pair of outer disk members that are rotatably mounted and over which the chain of frankfurters pass. A knife is provided adjacent the intermediate one of the disks which slits the casings of the frankfurters.
Brendle et al. discloses an apparatus in which the sausage is cut by bending the sausage into a curve and then drawing the outside, i.e., that portion having the longer radius, of the curved sausage along the cutting edge of a sharp cutting instrument. In one embodiment the sausage is not only flexed longitudinally, but the casing is pulled circumferentially away from the knife at the area of cutting to facilitate the cutting and assist in loosening the casing from the sausage.
Klyce discloses an apparatus for peeling a chain of sausages. The apparatus includes a substantially large-diametered power-driven wheel having a grooveway around the rim of the wheel. The apparatus includes means for guidingly constraining the chain of sausages in the grooveway of the wheel and for moving the sausage chain in an arced path around substantially a quarter sector of the wheel. The apparatus includes a plurality of successionally arranged means for acting on the sausages as they move along the curved path including oven means for heating the moving sausages, knife means for slitting the sausage casing of each sausage link, compressed air means for loosening the casing from the sausage meat kernel, and vacuum air means for remotely separating the string of meat-free casings from the meat kernels of the sausage chain.
While each of the above patents disclose various apparatuses for skinning frankfurters and the like, none disclose the apparatus and method of the present invention. More specifically, none of the references disclose apparatus for skinning the casing from a chain of encased frankfurters and the like comprising conveying means for loosening the casing of the frankfurters and at the same time conveying the frankfurters endwise in a moving chain of frankfurters along a sinuous path and for applying tension to the chain of frankfurters to provide at least a pair of stressing stations at which the chain of frankfurters is bent and the casing thereof is stressed at least along one side, and knife means provided at least at one of said stressing stations for slitting the stressed side of the casing of the chain of frankfurters as the chain moves by said one of said stressing stations.